APR 21, 2020 4:22 PM PDT

Virtual Cell Provides a Close Look at Gene Expression During Development

WRITTEN BY: Carmen Leitch

Living organisms start out as one cell, and its genetic programs allow it to divide many times over, giving rise to new cells and eventually, all kinds of tissues and structures.

The animation above shows a 4D visualization of single-cell expression patterns. Credit: Hanna Sladitschek/EMBL

"How are the many different cell types in the body generated during embryonic development from an egg, which is only a single cell? This is one of the most fundamental questions in biology," noted Dr. Pierre Neveu, a group leader at European Molecular Biology Laboratory (EMBL) Heidelberg, as he outlined the questions his research group seeks to answer.

Assessing cellular behavior at the molecular level through all the stages of an organism's development is a challenging task, however. The activity of many genes has to be carefully orchestrated over time to ensure that development proceeds as it should, and those genes may be regulated in several different ways. Gene activity also varies depending on the cell type and developmental stage.

"So far we have lacked a comprehensive understanding of the gene expression programs. These instruct individual cells to form the different cell types necessary to build an embryo," explained the first author of the study, Dr. Hanna Sladitschek, a former EMBL Heidelberg postdoc who is now at the University of Padua School of Medicine.

In this study, the researchers constructed a virtual embryo representing a marine organism called Phallusia mammillata. This animal is a sea squirt that lives in the Atlantic Ocean and the Mediterranean Sea. Every one of these organisms has the same number of cells, so observations taken from different specimens can be combined, making an analysis like this one far easier.

The researchers used single-cell transcriptomics that shows which genes are active on the level of an individual cell, and light-sheet microscopy to image their forms as they grew from one cell to 64 during seven rounds of cell division in early development.

"Our model shows that it is possible to know the location and history of an individual cell by analyzing its gene expression," said Neveu. "In addition, we find that while the regulation of gene expression is very precise within an embryo, differences in developmental timing explain the observed variation between individual embryos."

This work illustrates that gene expression is highly coordinated during development, and is similar among many embryos, which is likely also true for other species.

"Our studies represent a leap forward in the emerging field of developmental genomics," said study co-author Dr. Lars Hufnagel. "Now that we have worked with an organism with a small number of cells, it will, of course, be very interesting to extend our work to mammals, which have many more cells!"

In the time-lapse video above, check out a zebrafish embryo developing over 24 hours from one cell to as tiny animal.

Sources: AAAS/Eurekalert! via European Molecular Biology Laboratory, Cell

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
AUG 12, 2021
Technology
New Process for Making Pure Synthetic RNA
AUG 12, 2021
New Process for Making Pure Synthetic RNA
Researchers may have found a way to create synthetic RNA that is more “pure” and cost-effective than previou ...
AUG 27, 2021
Cell & Molecular Biology
Common Pesticide May Lead to Weight Gain
AUG 27, 2021
Common Pesticide May Lead to Weight Gain
Globally, obesity rates have been rising for years. Research has indicated that a western diet that's high in fat, sugar ...
SEP 03, 2021
Cell & Molecular Biology
Is a Venom-Like Molecule Involved in COVID-19 Mortality?
SEP 03, 2021
Is a Venom-Like Molecule Involved in COVID-19 Mortality?
Scientists have sought to learn more about why some people get severe COVID-19 while others have only mild cases. We kno ...
SEP 07, 2021
Immunology
Designer Cells for Treating Arthritis Are Activated by Inflammation
SEP 07, 2021
Designer Cells for Treating Arthritis Are Activated by Inflammation
Scientists have developed a new cell therapy for arthritis that becomes activated in the presence of inflammation. When ...
SEP 07, 2021
Cell & Molecular Biology
Genetic Influences That Help Make the Human Brain Unique
SEP 07, 2021
Genetic Influences That Help Make the Human Brain Unique
For years, many researchers have been trying to answer the question "What makes us human?" from both a biological and ph ...
SEP 27, 2021
Genetics & Genomics
DNA Gives Clues to the Mystery of 'Skeleton' Lake
SEP 27, 2021
DNA Gives Clues to the Mystery of 'Skeleton' Lake
While this research has provided some answers, it also raised many new questions. An image by Atish Waghwase/Harney et a ...
Loading Comments...